Cryosphere glossary
A type of Pleistocene-age (formed 1.8 million to 10,000 years before present) permafrost that contains a significant amount of organic material with ice content of 50 to 90 percent by volume. Thawing yedoma is a significant source of atmospheric methane.
Image
![https://nsidc.org/sites/default/files/cryosphere/glossary/yedoma_small.jpg yedoma_small.jpg](/sites/default/files/styles/large/public/2020-12/yedoma_small.jpg.webp?itok=zIiDugjc)
A yedoma in Russia shows the thick layer of ice and carbon material exposed along this body of water.
Vladimir Romanovsky
a general category of ice that represents the transition between nilas and first-year ice; usually 10 to 30 centimeters (4 to 12 inches) thick.
the ratio of increase in stress acting on a test specimen, to the resulting increase in strain, under constant transverse stress.